Leakproof dry cell



Oct. 17, 1944. G. BERIGAN LEAK-PROOF DRY CELL Filed Aug. 24, 1942Patented Oct. 17, 1944 LEAKPRooF par CELL Leroy G. Berigan, Madison,Wis., assignor to Ray-O-Vac Company, a corporation of WisconsinApplication August 24, 1942, Serial No. 455,823

(Cl. 13G-133) 3 Claims.

'Ihis invention relates to leak-proof dry-cells of the type used inflashlights and more particularly to improved telescoping protectiveshells which form the outer casing.

The primary object of the invention is to provide an improved dry-cellwhich will not swell or leak suiiiciently to damage a iiashlight casingor other equipment with which the cell may be used.

Another object of the invention is' to provide an improved leak-proofdry-cell which is capable of withstanding great internal pressure butdoes not require a metal outer jacket.

A further object of the invention is to provide improved lockingconnections between the outer shells of the unit and their associatedmetal end terminals.

The invention is illustrated in a preferred embodiment in theaccompanying drawing in Which- Figure 1 is a fragmentary verticalsectional view of a dry-cell embodying the invention, taken as indicatedat line I of Figure 2.; Figure 2 is a top plan view of the cell; andFigure 3 is an exploded view, with some of the parts in section, showinghow the casing is assembled.

In the embodiment illustratedl a zinc electrode 4, which may be in theform of a cup, is provided with a central carbon electrode 5 surroundedby a bobbin 6 of depolarizing mix, im-

mersed in electrolyte 1. An insulating washer 8 is provided in the upperportion of the zinc electrode and is impaled by the carbon electrode 5.Suitable sealing material il may be provided t0 close the upper portionof the zinc cup.

A metal disc Ill forms the bottom of the unit and is in electricalcontact with the zinc electrode l. A shell Il is in the form of acylinder and preferably is of strong fibrous material such as craftpaper and which has been treated to render it moisture resistant andelectrically non-conductive. 'Ihe lower marginal portion of the shell II is curled inwardly and makes a tight interlocking connection with themarginal portion of the disc .III as indicated at I2.

A metal top I 3' is preferably provided with a socket Il to tightlyembrace the carbon electrode 5. Another cylindrical shell ofnon-conductive material I5 is secured by an interlocking connection tothe metal top, as indicated at I6, and has Van internal diameter whichis slightly larger than the exterior of the shell Il so that a tighttelescoping fit may be made.

After the carbon electrode 5 and the depolarizing mix havebeenintroduced into the zinc cup 4 and the sealing material 9 applied,the assembly is thrust downwardly into the shell II until the zincelectrode contacts the bottom terminal I0. The upper marginal portionsof the shell Il are then turned inwardly over the upper end ners whichprevent damage to the metal parts even though subjected to rather roughhandling.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, for some modiiications will be obvious to those skilled inthe art.

What I claim as new, and desire to secure by Letters Patent, is: W'

1. A leak-proof dry-cell provided with circuit terminals at oppositeends, comprising: a hollow cylindrical zinc electrode containingelectrolyte;

a centrally disposed carbon electrode and depolarizing mix in saidelectrolyte: a metal base electrically connected to said zinc electrodeand forming an exposed bottom terminal for and of less diameter than thezinc electrode; a= strong cylindrical shell of moisture resistant,electrically non-conductive material extending uP- wardly around thezinc electrode and having its lower marginal lportion interlocked withand sealed in the marginal portion of said metal base; a metal top ofless diameter than the zinc electrode and electrically connected to saidcarbon electrode and forming a top terminal therefor; and a strongcylindrical shell of moisture resistant, electrically non-conductivematerial having its upper marginal portion interlocked with and sealedin the marginal portion of said metal'top and having its side wallsextending downwardly in telescoping relation with the first mentionedshell and cemented thereto so vas to make a tight permanent connectiontherewith. i

2. A dry-ceu as specified m claim 1, in which' the cylindrical shell,which is locked to the base terminal, is co-extenslve with and tightlyembraces the side walls of the zinc electrode and is overlapped by thecompanion coextensive telescoping shell which is locked to the topterminal.

3. A dry-cell as specified in claim l, in which the interlockingconnection between each nonconductive shell and its end terminal isformed by curling the shell inwardly into an interlocking grip with themetal terminal and thereby presenting a rounded insulated shoulderportion, reinforced with metal, at each end of the cell.

LEROY G. BERIGAN.

